NEW YORK (TheStreet) -- McDonald's (MCD) is taking its all-beef patties to a new level. You may have heard this elsewhere, but McDonald's wants to serve your burger your way. And try to increase what you spend on your visit, too.

In fact, the monster fast food chain is testing burger customization having it your way at Ronald's -- in two locations targeting millennials and other hungry folks by allowing them to customize their burger using tablets before they get in line.

Tapping in to e-technology, McDonald's in the test allowed customers to select their bun, patty, cheese and toppings. The burgers are assembled fresh moments after the specialized order is received.

In tests, McDonald's saw strong dinner crowds and average customized burgers -- chose from more than 20 premium toppings -- sold for $1 more than standard burger offerings on the menu.

McDonald's is expanding its current test. The option is not expected to link up at the more than 14,000 McDonald's, but if you add up all those extra dollars, it may tempt a corporate culture change.

Oddly, the build-your-own burger concept flies in the face of its assembly line economies. McDonald's perfected fast food with excellence in speed, convenience, price and value. Now with strong competition in fast casual and a new business class of millennnials who want good food fast, McDonald's is struggling to keep up with its own ideals.

McDonald's could certainly use the boost of new burger sales. In the last fiscal year, global sales rose only 0.2%. This was powered by new stores and rebounding sales in the European region. U.S. sales at stores open more than a year declined 1.4% in the fourth quarter. In 2014, same store sales continue to fall. February U.S. same store sales fell 0.3%.